My wife and I are taking our first trip on Amtrak this summer, TWO-BUF-CHI-MAL and returning on the same route a couple of weeks later, with a roomette booked on the Empire Builder each way. When I was booking our trip at 800-USA-RAIL the service rep couldn't process my Canadian credit card - she said the computer wouldn't allow it without a zip code, which we don't have here in Canada. I had to go to the Via/Amtrak desk in Toronto to pay for the trip. My question is, does anyone have an experience using a Canadian credit card onboard an Amtrak train? I would only use it if we decided to upgrade on a particular leg of the trip. Thanks.